Malicious PDF — malware analysis report

Static analysis result for SHA-256 d3770651d70711c7…

MALICIOUS

PDF

75.3 KB Created: 2021-09-12 17:07:06 +03:00 Authoring application: wkhtmltopdf 0.12.5 (via Qt 5.11.3)
MD5: 81bea3849a809e8679ac5170e42ffcdf SHA-1: 06cff6b0c4d634641ced71948ebd055b86c9510e SHA-256: d3770651d70711c74f7669736eb66e1c339f3dae8df55fad2c4f479e0bd50232
156 Risk Score

Malware Insights

MITRE ATT&CK
T1566.001 Spearphishing Attachment

The file was detected by ClamAV as Pdf.Phishing.Trojan and flagged by an ML classifier with high confidence. It contains numerous embedded URLs pointing to various domains, many of which appear to be compromised WordPress sites or disposable hosting, suggesting a link farm or redirection mechanism. The presence of PDF-specific heuristics like PDF_URI and PDF_SEO_DISPOSABLE_LINK_FARM further supports its malicious nature as a phishing or malware distribution lure.

Machine Learning

  • Nyx PDF Classifier malicious score 0.9948

Heuristics 6

  • ClamAV: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0 critical CLAMAV_DETECTION
    ClamAV detected this file as malware: Pdf.Phishing.Trojan-d2528dad23a95d95-d2528dad23a95d95-10044376-0
  • PDF link farm points to compromised-WordPress upload storage medium PDF_COMPROMISED_CMS_UPLOAD_LINK_FARM
    PDF contains multiple clickable links, across many distinct hosts, whose targets are random-slug files parked in the upload directories of vulnerable WordPress form plugins (FormCraft, Super Forms). This is the hallmark of the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains hosted on compromised sites. The PDF itself carries no exploit — the risk is the linked destinations.
  • Small PDF is a non-clustered link farm on disposable hosting medium PDF_SEO_DISPOSABLE_LINK_FARM
    Small PDF contains many clickable external PDF links spread thin across many distinct hosts (no single dominant host), corroborated by a utm_term SEO-redirector link and/or links parked on free/disposable content hosts. This is the 'free document/template' SEO phishing PDF family, which ranks for search queries and routes users into payload/redirect chains, rather than a normal document citation pattern. The PDF itself carries no exploit — the risk is the linked destinations.
  • External URI info PDF_URI
    PDF contains an external URL action
  • Object number defined twice with different bodies info PDF_DUPLICATE_OBJ_BODY_INCREMENTAL
    The same indirect object (N G) is defined more than once with different body bytes. First-wins and last-wins readers will resolve different content, which is a parser-confusion shape used by targeted PDFs. Body-only differences are common in benign incremental updates, so severity is raised only when the duplicate carries active content.
  • Embedded URL info EMBEDDED_URL
    One or more URLs were extracted from the document. The URL itself is not a detection — see the per-URL labels for which channel (macro, JS, link annotation, document body, ...) reached each URL.
    URL https://nomylo.ru/uplcv?utm_term=borderlands+2+rough+rider+shield
    • https://mepho.hu/ckfinder/userfiles/files/pigetizasarovawixejip.pdf
    • https://cafesca.info/ckfinder/userfiles/files/putudel.pdf
    • http://www.goataxiservice.com/wp-content/plugins/formcraft/file-upload/server/content/files/16132493476f34---25653417146.pdf
    • http://peak-experience-japan.com/images/blog/file/25907467794.pdf
    • http://elisa5888.com/shopadmin/upload/files/puwuk.pdf
    • https://juniorclublivorno.com/sitonews/images_upload/files/kujikil.pdf
    • https://thehamptonsbloomington.com/wp-content/plugins/formcraft/file-upload/server/content/files/1613b913950721---52292831915.pdf
    • http://ensky-chemical.com/upload/files/78389700225.pdf
    • http://yugreat.com/filespath/files/20210907144744.pdf
    • https://www.fishhabitatnetwork.com.au/application/third_party/ckfinder/userfiles/files/19378855646.pdf
    • https://www.lipca.com/ckfinder/userfiles/files/79987357266.pdf
    • https://buddingheights.org/wp-content/plugins/formcraft/file-upload/server/content/files/1613d363c7000c---30008380364.pdf
    • http://synhbio.com/upload/files/86353829373.pdf
    • http://suliaok.com/v15/Upload/file/20219111759442694.pdf
    • http://hferrynetworks.com/FileData/ckfinder/files/20210907_EC1541C0F9FF6FDB.pdf
    • http://www.azurwelcomeservices.com/userfiles/file/26685234170.pdf
    • http://moskvaznaet.ru/upload/files/vegorerikoxokakilosuxot.pdf
    • http://rowadhr.com/app/webroot/upload/files/tadidowibepa.pdf
    • http://fotofolliasanlazzaro.it/userfiles/files/romowasirageve.pdf
    • http://showdoimovel.com/files/files/rekakupon.pdf
    • http://vijyaiprismcrm.com/userfiles/files/jajiwiziredopiput.pdf
    • http://orthocarecentroortopedico.it/userfiles/files/jexojodosif.pdf
    • https://jazykovytabor.topenglish.sk/app/webroot/gallery/files/relebokuvose.pdf
    • http://areawifi.com/DESARROLLO/userfiles/files/4123307176.pdf
    • http://www.w3.org/1999/02/22-rdf-syntax-ns#
    • http://purl.org/dc/elements/1.1/
    • http://ns.adobe.com/pdf/1.3/
    • http://ns.adobe.com/xap/1.0/
    • http://ns.adobe.com/xap/1.0/mm/
    • http://ns.adobe.com/xap/1.0/rights/
    • http://dejavu.sourceforge.net
    • http://dejavu.sourceforge.net/wiki/index.php/License

Extracted artifacts 3

Files carved from inside the sample during analysis.

FilenameKindSourceSize
font_00_sfnt_off0000c3ae.bin
8156e99b61c384c3cf3d44fd94c562fa71af13c29557cacf3609079812145dae
pdf-font-stream PDF embedded font (sfnt) at offset 0xC3AE 10704 bytes
font_01_sfnt_off0000dbfe.bin
9d2294e344127da9ddc2b77d68b1576b6b78373885bc9da2859f180a98f2c1e1
pdf-font-stream PDF embedded font (sfnt) at offset 0xDBFE 16792 bytes
font_02_sfnt_off0000f410.bin
f53e3f0bb103d93c60a099f96994d5a58317e80d3f9922f4b92c2b7917a07790
pdf-font-stream PDF embedded font (sfnt) at offset 0xF410 16972 bytes